Phase-2 Slice 12b.
- Expanded view-mode: replaced the "Inline tracks coming soon" placeholder with
real per-item inline track expansion. Matches Tauri 1:1 (no chevron -- every
album/playlist row auto-shows its tracks). fetch_item_tracks reuses the shared
ProdItemResolver (display-only; spec §8 routing matrix); renders the app's
TrackRow indented; inline-track media actions (play/play-next/play-later/go-to).
- skip-to-item: headless myqbz_play::skip_to_next_item/skip_to_previous_item over
the qbz-core queue using the crate's next_item_index/previous_item_index (3s prev
rule). UI trigger DEFERRED -- Tauri has zero frontend callsites for skip-to-item
(no skip-album button exists), so wiring one would invent UI; the global next()/
previous() are untouched.
Known polish (S12 fidelity pass): expanded-mode per-item cache should key on
source|source_item_id (survive filter/sort) + viewport-gate; inline go-to uses
item_type; duration "--:--". Backend crates untouched. cargo check green.
cc